Method and device for determining the quality of a speech signal
First Claim
1. Method for determining, according to an objective speech measurement technique, the quality of an output signal (Y(t)) of a speech signal processing system with respect to a reference signal (X(t)), which method comprises a main step of processing the output signal and the reference signal, and generating a quality signal (Q), wherein the processing main step includes:
- a first scaling step (S(Y+Δ
);
S(Y+Δ
i), with i=1,2) for scaling a power level of at least one signal of the output and reference signals by applying a first scaling factor which is a function of a reciprocal value of a first power related parameter of the at least one signal, and a second scaling step carried out by applying a second scaling factor (Sα
(Y+Δ
);
Sα
i(Y+Δ
i), with i=1,2;
Vα
3(Y+Δ
3, t);
Vα
3(Y+Δ
3)) which is a function of a reciprocal value of a second power related parameter of the at least one signal, using at least one adjustment parameter (α
,A;
α
i,Δ
i with i=1,2;
α
3,Δ
3).
1 Assignment
0 Petitions
Accused Products
Abstract
Objective measurement methods and devices for predicting perceptual quality of speech signals degraded in speech rocessing/transporting systems may have poor prediction results for degraded signals including extremely weak or silent portions. Improvement is achieved by applying a first scaling step in a pre-processing stage with a first scalins factor (S(Y+Δ), which is a function of the reciprocal value of the power of the output signal increased by an adjustment value (Δ), and by a second scaling step with a second scaling factor (Sα(Y+Δ); Sαi(Y+Δi), with i=1, 2), which is substantially equal to the first scaling factor raised to an exponent having a adjustment value (α) between zero and one. The second scaling step may be carried out on various locations in the device. The adjustment values are adjusted using test signals with well defined subjective quality scores.
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Citations
30 Claims
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1. Method for determining, according to an objective speech measurement technique, the quality of an output signal (Y(t)) of a speech signal processing system with respect to a reference signal (X(t)), which method comprises a main step of processing the output signal and the reference signal, and generating a quality signal (Q),
wherein the processing main step includes: -
a first scaling step (S(Y+Δ
);
S(Y+Δ
i), with i=1,2) for scaling a power level of at least one signal of the output and reference signals by applying a first scaling factor which is a function of a reciprocal value of a first power related parameter of the at least one signal, anda second scaling step carried out by applying a second scaling factor (Sα
(Y+Δ
);
Sα
i(Y+Δ
i), with i=1,2;
Vα
3(Y+Δ
3, t);
Vα
3(Y+Δ
3)) which is a function of a reciprocal value of a second power related parameter of the at least one signal, using at least one adjustment parameter (α
,A;
α
i,Δ
i with i=1,2;
α
3,Δ
3). - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. Device for determining, according to an objective speech measurement technique, the quality of an output signal (Y(t)) of a speech signal processing system (10) with respect to a reference signal (X(t)), which device comprises:
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pre-processing means (12) for pre-processing the output and reference signals, processing means (13, 14) for processing signals pre-processed by the pre-processing means and generating representation signals (R(Y), R(X)) representing the output and reference signals according to a perception model, and signal combining means (15, 16) for combining the representation signals and generating a quality signal (Q), the pre-processing means including first scaling means (21;
31, 32;
41, 42) for scaling a power level of at least one signal of the output and reference signals (Y(t), X(t)) by applying a first scaling factor (S(X,Y);
(S(Pf,Y);
S(Y+Δ
)), which is a function of a reciprocal value of a first power related parameter of the at least one signal,wherein the device further comprises second scaling means (43, 44;
51;
52;
61;
62) for a scaling operation carried out by applying a second scaling factor (Sα
(Y+Δ
);
Sα
i(Y+Δ
i), with i=1,2;
Vα
3(Y+Δ
3,t);
Vα
3(Y+Δ
3)), the second scaling factor being a function of a reciprocal value of a second power related parameter of the at least one signal, using at least one adjustment parameter (α
,Δ
;
α
i,Δ
i with i=1,2;
α
3,Δ
3). - View Dependent Claims (22, 23, 24, 25, 26, 27, 28, 29, 30)
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Specification